Non-sequitur graffiti has been the rage in Toronto for a while “ the Val Kilmer faces that showed up a couple of years ago being the most notable example “ but someone recently gave the fad a literary spin, as reported by Torontoist.com:

It seems that some Toronto taggers are no longer content to scrawl their own names on blank concrete canvases around the city and are trying instead to make more of a cultural statement. Last year, references to composer Gustav Mahler popped up in several places around town. This year, a more cryptic stencil has appeared on the Humber Bay Arch Bridge, boldly proclaiming “ISBN 486-28495-6” for all to see and ponder. This International Standard Book Number turns out to be a paperback edition of Henry David Thoreau’s Walden; Or, Life in the Woods.

Making it a reference to the Dover paperback edition is a nice, democratic touch. Even when book nerds go bad, they’re still nerds.

(And being nerds ourselves, we have to note that the ISBN is actually 0-486-28495-6.)